CAJ | 학술논문

目的采用猪的3个主动脉无冠瓣进行匹配组合,然后缝制成新型的无支架主动脉瓣膜,体外脉动流和动物体内植入对其进行测试.方法采集带有完整升主动脉的新鲜猪心脏,修剪之后保留升主动脉和二尖瓣前瓣及部分室间隔.用0.6%戊二醛进行主动脉根部预扩张和瓣叶零压力差固定之后,分别取3个大小和形态相似的无冠瓣进行拼接缝制,瓣膜的外侧和下缘覆以薄层牛心包.体外脉动流对制作的无支架猪主动脉瓣膜进行有效开口面积(EOA)和跨瓣压差(AP)测试,与同型号有支架牛心包瓣做对照.在体外循环下,用无支架瓣膜替换16只幼年绵羊的主动脉瓣膜,术中经食管内超声、术后定期经胸超声监测瓣膜的功能情况,并进一步观察动物的生存状况以及瓣膜的病理变化.结果新型无支架瓣膜消除了右冠瓣下方的肌肉组织,增加了瓣膜的有效开口面积.体外脉动流测试结果表明,无支架猪主动脉瓣的EOA在各个流量点均高于同型号的有支架牛心包瓣(均P<0.05),而平均跨瓣膜压差(△P)则明显低于有支架牛心包瓣(均P<0.05).16只实验动物有12只术后存活,其中有5只存活大于90 d,3只超过180 d,2只超过360 d.术中超声检查证实所有无支架瓣膜活动情况良好,均没有反流,跨瓣压差低[(3.90±0.78)mm Hg].术后15～360 d经胸超声显示瓣膜的启闭功能良好.分别在术后5、15、45、90、180和300 d处死动物,病理检查显示,无支架瓣膜有轻到中度的钙化,没有瓣周漏和组织过度增生.结论新型无支架猪主动脉瓣膜具有优良的血液动力学性能,手术植入相对简单,瓣膜具有较低的跨瓣压差.
목적 채용저적3개주동맥무관판진행필배조합,연후봉제성신형적무지가주동맥판막,체외맥동류화동물체내식입대기진행측시.방법 채집대유완정승주동맥적신선저심장,수전지후보류승주동맥화이첨판전판급부분실간격.용0.6%무이철진행주동맥근부예확장화판협령압력차고정지후,분별취3개대소화형태상사적무관판진행병접봉제,판막적외측화하연복이박층우심포.체외맥동류대제작적무지가저주동맥판막진행유효개구면적(EOA)화과판압차(AP)측시,여동형호유지가우심포판주대조.재체외순배하,용무지가판막체환16지유년면양적주동맥판막,술중경식관내초성、술후정기경흉초성감측판막적공능정황,병진일보관찰동물적생존상황이급판막적병리변화.결과 신형무지가판막소제료우관판하방적기육조직,증가료판막적유효개구면적.체외맥동류측시결과표명,무지가저주동맥판적EOA재각개류량점균고우동형호적유지가우심포판(균P<0.05),이평균과판막압차(△P)칙명현저우유지가우심포판(균P<0.05).16지실험동물유12지술후존활,기중유5지존활대우90 d,3지초과180 d,2지초과360 d.술중초성검사증실소유무지가판막활동정황량호,균몰유반류,과판압차저[(3.90±0.78)mm Hg].술후15～360 d경흉초성현시판막적계폐공능량호.분별재술후5、15、45、90、180화300 d처사동물,병리검사현시,무지가판막유경도중도적개화,몰유판주루화조직과도증생.결론 신형무지가저주동맥판막구유우량적혈액동역학성능,수술식입상대간단,판막구유교저적과판압차.
Objective To investigate the effects of a newly developed composite stentless porcine aortic valve constructed from noncoronary leaflets of three porcine aortic valves.Methods Fresh porcine hearts with ascending aorta were obtained from a slaughterhouse.The porcine aortic roots with ascending aorta and anterior leaflet of mitral valve and partial ventricular septum were dissected out and were pressurized to maintain their natural anatomical shapes with the leaflets floating freely at zero-pressure.Three noncorcnary leaflets fixed in 0.6% glutaraldehyde were carefully matched for size and symmetry to construct a novel composite stentless porcine aortic valve.The lower margin and outside of the valve was covered with a piece of bovine pericardium.The novel stentless valves were tested in vitro pulsatile flow to detect the effective orifice area (EOA) and mean pressure difference (△P) of the valve compared with the stented bovine pericardial bioprostheses of the same size.Sixteen male juvenile sheep underwent implantation of the novel valves in the supra-annular position in under cardio-pulmonary bypass.The intraoperative and postoperative echocardiography and pathological specimen were given to evaluate the hemodynamic performance and observed in the respects of a long-term survival,function of valve and pathological specimen.Results Since novel valves had the unfavorable muscle-based right coronary leaflet characteristic of porcine valve removed it had larger EOA.Pulsatile flow testing indicated that the EOA of the 3 novel valves was (3.47 ± 0.15),(3.69 ± 0.11 ),and ( 3.92 ± 0.18 ) cm2 respectively,all significantly greater than those of the stented bovine pericardial biopresthesis [ ( 2.00 ± 0.16),( 2.21 ± 0.26),and ( 2.37 ± 0.42) cm2 respectively] at each integral simulated cardiac output between 3-6 L/min (all P < 0.05), while the △p levels of the novel valves were (2.35±0.41 ),(3.10 ±0.20),and (3.56±0.16) mm Hg respectively,all significantly lower than those of the stented bovine pericardial biopresthesis [ (4.98 ± 0.46),(6.82 ± 1.27),and ( 8.40 ± 1.83 ) mm Hg respectively,all P < 0.05 ].Twelve of the sixteen sheep survived after operation.Five of them had lived for more than 90 days,3 more than 180 days,and 2 more than 360 days.The intra-operative echocardiographic analyses showed low △P [ ( 3.90 ± 0.78 )mm Hg] and no regurgitation in all sheep.After 15 to 360 days,all valves performed excellently.The sheep were postoperatively sacrificed in 5 d,15 d,45 d,90 d,180 d,or 300 d respectively.Necropsy revealed the valves had a low to mild level of calcification,without periprosthetic leakage and overgrowth of fibrous tissue.Conclusion The newly developed composite stentless porcine aortic valves show excellent hemodynamic performance with lower transvalvular pressure gradient and are relatively easy to implant.